The present invention relates to a control system for welding applications. In particular, the present invention relates to a control system for depositing powder in a molten puddle.
Welding applications use an energy source or laser to melt a molten puddle. For deposition welding, layers of a weld material or powder are deposited into the molten puddle to form three-dimensional objects. Powder is dispersed from a nozzle which is aimed to deposit the powder into the molten puddle. The molten puddle cools to solidify the fused powder to form the three-dimensional object. For optimum operation, it is desirable to accurately aim the powder dispersed from the nozzle so that all of the powder is deposited to a desired location(s) in the molten puddle. Powder deposited outside the molten puddle or improperly can have certain deleterious effects on the metallurgical properties and performance of the resulting structure as well as increased costs.
Various variables can affect powder aiming or deposit to the molten puddle, including nozzle or laser standoff from the workpiece and feed parameters for powder dispersed from the nozzle. During operation, the position of the laser or nozzle can shift or other parameters can vary as a result of the high operating temperatures. Variations in the operating parameters can affect aiming of the powder into the molten puddle.
In prior applications, the weld area is visually inspected to assure accurate deposit of the powder into the molten puddle. However, such visual inspection is not systematically controlled. Prior systems which provide size and dimension control of the puddle based upon a puddle image do not provide a complete control solution for accurately aiming powder into the molten puddle. The present invention addresses these and other problems and provides solutions not recognized nor taught by the prior art.
The present invention relates to an imaging system for controlling powder aiming into a molten puddle. In the imaging system of the present invention, an image processor extracts a first image of the molten puddle and a second image of a powder envelope from a captured image of the weld area. The first and second processed images provide feedback for process control.